<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html>
 <head>
  <title>Syntax and parsing of unknown pseudo-classes</title>
  <style type="text/css">
  p { background: lime; }
  p:subject { background: red; } /* this is not valid CSS, and if UAs
  implemented the experimental :subject pseudo-class they should have
  used the :-vnd-ident syntax. */
</style>
  <link rel="first" href="css3-modsel-1.html" title="Groups of selectors">
  <link rel="prev" href="css3-modsel-159.html" title="Syntax and parsing of new pseudo-elements">
  <link rel="next" href="css3-modsel-161.html" title="Syntax and parsing of unknown pseudo-classes and pseudo-elements">
  <link rel="last" href="css3-modsel-d4.html" title="Dynamic updating of :first-child and :last-child">
  <link rel="up" href="./index.html">
  <link rel="top" href="../../index.html">
 </head>
 <body>
 <p>This line should have a green background.</p>
</body>
</html>